The field of the disclosure relates generally to satellite communications, and more particularly relates to methods and apparatus for routing Internet Protocol (IP) packets in a satellite network.
A typical modern transponded (or “bent-pipe”) satellite has a metal or composite frame that houses a power source (e.g., one or more batteries, solar cells, and/or the like) and various electronic components, as well as one or more antennas. The components generally include one or more “transponders” that contain one or more radio receivers, frequency translators, and/or transmitters. The total bandwidth of the satellite is based on the number of transponders. For example, one known commercially-available satellite has a total available bandwidth of 3,528 MHz divided across forty-five C-band and sixteen Ku-band transponders. Such transponders are collectively referred to as “the payload” of the satellite.
A typical analog transponded communications payload receives multiple uplink beams from the earth or another satellite via an uplink antenna. Each received beam is amplified with a low noise amplifier (LNA) and down-converted (D/C) for additional processing. The down-converted beams can then be switched, multiplexed (MUX) or otherwise routed and combined prior to upconversion and re-transmission to the Earth or another satellite.
Digital satellite payloads generally function in either a channelized manner or a regenerative manner. A channelized payload emulates traditional fixed analog transponders, but also includes the ability to finely divide, control, and monitor bandwidth and power allocation onboard the satellite. Digital transponded payloads normally have flexible switching of inputs to outputs. Transponded channels are merely repeated signals, without any modification. Accordingly, transponder payloads can carry any type of signal without regard to format or modulation mode. Digital transponder systems may be relatively easily modified to be backward compatible with analog transponder systems. Unlike transponded payloads, regenerative payloads can perform demodulation and remodulation of uplinked signals. In such systems, the user signal and the user data embedded in the signal are recovered and processed to enable the payload to act upon the user data in a desired manner. Embedded data has historically been used for autonomous switching in packet or frame-based systems and/or for security functions. In particular, error detection and correction can be performed on the embedded data before it is retransmitted. However, because of their requirements for specific signal and data types, regenerative systems are generally not backward compatible.